This invention relates generally to incandescent electric lamps and more particularly to an improvement which precludes the use of incandescent electric lamps of excess wattage in those fixtures wherein incandescent lamps of a predetermined limited wattage are to be used.
There are many incandescent lamp receiving fixtures wherein lamps of a predetermined limited wattage are to be utilized. For example; in many fixtures, if lamps of a high wattage are inserted and illuminated, the heat generated by the incandescent electric lamp may damage a portion of the fixture; such for example as the shade. Alternatively, it has been determined that in some instances damage resulting to the socket can result in a short circuit which in turn leads to a fire. In other instances, enclosures receiving the electric lamp may be damaged or alternatively sufficient heat generated such that damaged or alternatively sufficient heat generated such that those coming in contact with the fixture may possibly injure themselves.
At the present time, all incandescent electric lamps designed for illumination by standard household current of 110 volts have a standard threaded base adapted to be received within a threaded socket irrespective of the wattage of the bulb. As a result, even though a particular fixture is designed to receive an incandescent electric lamp of limited wattage, there is no known means for precluding the user from inserting an incandescent lamp having an excess wattage into that particular fixture.
There are numerous polarizing devices utilized in electrical connectors to assure proper interconnection of the male and female contacts thereof, such for example as those shown in U.S. Pat. No. 3,582,867 and 3,885,849. There are also known modifications to the traditional electric lamp socket to adapt it to receive lamps of various construction other than the standard incandescent electric lamp, such for example as those shown in U.S. Pat. No. 4,683,402 which adapts such a socket to receive fluorescent lights and U.S. Pat. No. 3,356,984 which allows a bulb to be inserted or removed by axial movement as well as U.S. Pat. No. 438,310 which illustrates various modifications of the electric lamp base for receipt in various configurations of electric lamps sockets. Applicant, however, is unaware of any prior art which teaches a structure adapted to limit the wattage of an incandescent electric lamp receivable within a socket therefor.